硅酸盐矿物对磷钼酸铯的固化性能研究

Study on Solidification Property of Silicate Mineral for Cesium Phosphomolybdate

针对硅基磷钼酸铵(AMP/SiO_(2))吸附剂在分离模拟高放废液中Cs后的处理,以矿物水铝英石、丝光沸石、4A型沸石以及斜发沸石为固化基材,采用冷压/烧结工艺制备了硅酸盐陶瓷固化体。分析了固化体的微观形貌、物相组成和表面元素分布,并探讨了固化体的固化机理、抗浸出性能和耐辐照稳定性。结果表明:1 200℃下烧结所得固化体的表面均出现熔融现象,结构更加致密;水铝英石烧结固化体中形成了铯榴石-CsAlSi_(2)O_(6)晶相,可有效抑制Cs的挥发,Cs固定率达93.1%。500 kGyγ射线辐照后,固化体中的主要晶相均未发生变化,且在25℃去离子水中浸出后,Cs的浸出百分比仅为0.79%。

For the treatment of silica based ammonium molybdophosphate(AMP/SiO2)adsorbents after separation of cesium from simulated high level liquid waste,allophane,mordenite,zeolite 4 A and clinoptilolite were respectively chosen as the base materials to synthesize the silicate ceramic solidified bodies with pressing/sintering method.The microstructure,phase composition and surface element distribution of the solidified bodies were analyzed.The solidification mechanism,leaching resistance and radiation resistance of the solidified bodies were also discussed.The surface of the solidified bodies appears melting phenomenon at 1200℃,and the structure is more compact.The pollucite crystal phase(CsAlSi2O6)is recrystallized in the allophane based solidified body,which can effectively suppress the volatilization of the cesium element,and the cesium immobilization ratio reaches 93.1%.With the irradiation of 500 kGyγray,there is no change of the main crystal phases of the solidified body,and the leaching percentage of Cs is only 0.79%after leaching in deionized water at 25℃.